Award: OCE-1315201

Human activity is releasing CO2 into the atmosphere are a very rapid rate. Some of the additional CO2 dissolves in, and reacts with the ocean, driving down pH at an unprecendented rate: the phenomenon of ocean acidification. We have limited understanding of how this will affect ocean ecosystems. How will it affect the phytoplankton that fix CO2 into organic molecules, maintain fisheries, and mediate a long term oceanic storage of carbon? Acidification can affect plankton population growth positively, by making more CO2 available for the organisms to fix, or negatively because the pH change has a detrimental effect on their biochemistry. In this project we compiled data on these effects from laboratory experiments with different species of phytoplankton. We encoded the experimental results in a computer simulation of plankton in the global ocean and examined the results. The simulations suggest significant shifts in the geography of different plankton species in response to acidification, but not a significant change in overall productivity and function. However, the computer model is very simplistic and, notably does not account for the potential for genetic adaptation of the plankton to the new environment. New, ongoing laboratory experiments to explore the evolutionary response to adaptation will inform further simulations and clearer understanding. Last Modified: 02/15/2019 Submitted by: Michael J Follows